This invention relates generally to methods and apparatuses for fabricating plastic sleeves and more particularly to a method and device in which a blank of plastic film is wrapped around the cylindrical outer surface of each of a plurality of cylindrical mandrels of a unique design of a turret assembly, the ends of the blank being overlapped. The overlapped ends are fused by heat sealing thereby to form a plastic sleeve, and this sleeve is easily slipped off the mandrel.
Recently, there has appeared the practice of fitting a sleeve of a plastic film with a decorative pattern applied beforehand thereon onto the outer surface of a glass bottle and placing this glass bottle thus covered with the sleeve in a heating oven thereby to cause the film to undergo heat shrinkage and thereby to adhere tightly to the surface of the glass bottle. In the fabrication of the above described sleeve of plastic film, a blank of the plastic film is wrapped around the cylindrical outer surface of a cylindrical mandrel, the wrapping length of the blank being sufficient to cause its ends to be overlapped when the blank is thus wrapped, and the end edge parts thus overlapped are fused by heat sealing. The sleeve of the plastic film thus formed is stripped or caused to slide off the mandrel for removal therefrom and is then fitted onto a glass bottle and caused to adhere tightly thereto by the above mentioned heat shrinkage process step.
However, in the step of removing the plastic film sleeve from a conventional mandrel and fitting the sleeve onto a glass bottle, there have heretofore been frequent cases wherein the plastic sleeve could not be easily removed from the mandrel. While various reasons for this difficulty are conceivable, the principal causes appear to be that the gap between the plastic sleeve and the mandrel is small, whereby the frictional force resisting removal is large and that, at the time of fusing by heat sealing, the overlapped part of the plastic sleeve melts and adheres to the outer peripheral surface of the mandrel.